Production of excited charm and charm-strange mesons at HERA

Abstract

The production of excited charm, D 1(2420)0 and D 2 * (2460)0, and charm-strange, D s1(2536)±, mesons in ep collisions was measured with the ZEUS detector at HERA using an integrated luminosity of 126 pb−1. Masses, widths and helicity parameters were determined. The measured yields were converted to the rates of c quarks hadronising as a given excited charm meson and to the ratios of the dominant D 2 * (2460)0 and D s1(2536)± branching fractions. A search for the radially excited charm meson, D *′(2640)±, was also performed. The results are compared with those measured previously and with theoretical expectations.